1. Field of the Invention
The invention relates to ski boots comprising a rigid shell having at least one foot retention system positioned in the interior, and relates in particular to a foot retention system with an action zone positioned on the forefoot.
2. Description of Background and Relevant Information
Numerous ski boots of this type, equipped with a foot retention system adapted to maintain the forefoot, have been developed.
There are known boots in which the foot retention system comprises maintenance means which at least partially surrounds the forefoot and means activating the maintenance means to apply it against the forefoot. For example, French Published Application Nos. 2,514,621, 2,576,192 and 2,419,690 show boots of this type. More particularly, the maintenance means consists of relatively flexible and wide straps for better distribution of the pressure and where the tension can be varied to cause the coming together of the liner on the foot, thus ensuring the retention of the foot in the rigid shell of the boot. These straps surround the foot, either totally, such as is described in French No. 2,576,192, or partially, such as is described in French No. 2,514,621, and are situated substantially in front of the zone of the instep to be applied against, in particular, the forefoot at the level of the metatarsals.
In the example of French No. 2,419,690, a foot retention system is disclosed as comprising two straps connected to a single tightening apparatus by means of a connecting rod which acts as a distribution plate. One of the straps extends in the zone of the instep and the other strap extends in the zone of the forefoot. Thus, by adjusting the tightening of the apparatus, one simultaneously ensures the retention of the forefoot and of the heel without differentiating the forces applied on the zones of the foot by virtue of the distribution of the forces at the level of the connecting rod.
These foot retention systems which have just been described are effective but nevertheless are disadvantageous because they act on the foot in a uniform manner over the entire pressure zone of the straps without avoiding certain sensitive lateral points of the foot such as the bony projection (apophysis styloid) of the fifth metatarsal, the connection between the metatarsal and the phalange, or the external arch. These sensitive points must in effect be protected from overly hard contact so as not to risk creating bone spurs, cramps, numbness, etc.